1. Field of the Invention
The present invention relates to a silicon die and, more particularly, to a hermetic seal for silicon die with a metal feed through structure.
2. Description of the Related Art
It is a common practice to permanently connect a silicon die to a semiconductor package. The package often has a multi-layered substrate with internal routing that provides an electrical connection between a number of package bonding pads on the top side of the package, and a number of pins or solder bumps on the bottom side of the package.
Inside the package, very fine bonding wires are used to provide an electrical connection between a number of die bonding pads on the top surface of the die, and the package bonding pads. The die bonding pads, in turn, are electrically connected to a semiconductor integrated circuit.
FIG. 1 shows a cross-sectional diagram that illustrates a conventional ball grid array package 100. As shown in FIG. 1, package 100 includes a substrate 110 that has a top surface 112 and a bottom surface 114. Substrate 110 also has a number of housing bonding pads 116 that are formed on top surface 112, and a number of contact pads 120 that are formed on bottom surface 114. In addition, substrate 110 has a number of solder balls 122 that are attached to contact pads 120, and internal routing 124 that electrically connects the housing bonding pads 116 to the solder balls 122 via the contact pads 120. Solder balls 122, in turn, are shown connected to a printed circuit board 126
As further shown in FIG. 1, package 100 also includes a die 130 that is attached to top surface 112 of substrate 110. Die 130, in turn, has a number of die bonding pads 132 that are electrically connected to a semiconductor integrated circuit. Package 100 additionally includes a number of very fine bonding wires 134 that connect the housing bonding pads 116 to the die bonding pads 132, and an encapsulant 136 formed over substrate 110 and die 130.
One advantage provided by package 100 is that the manufacturing process required to fabricate package 100 is well known and understood. Package 100, however, suffers from a number of well-known disadvantages. One drawback to housing 100 is that, although the manufacturing process required to fabricate package 100 is well known and understood, package 100 is nonetheless costly to fabricate.
Another drawback to package 100 is that bonding wires 134 have additional inductance which, in turn, decreases the performance of the semiconductor integrated circuit. Thus, there is a need for a method of connecting a die to a semiconductor package that is less expensive than conventional approaches, and eliminates the need for bonding wires.